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The discovery of new genomic regions related to blood pressure offers crucial insights for understanding and treating hypertension. May 17 is International Hypertension Day and on this occasion, This is Beirut provides an update on the latest developments.
Arterial hypertension (AHT) is a major worldwide public health issue. Without early diagnosis or proper treatment, it can lead to severe complications such as strokes, heart attacks, heart failure, kidney damage and many other health issues.
In its first global report on AHT, published in September 2023, the World Health Organization (WHO) issued a stark warning, identifying it as a “race against a silent killer.” Between 1990 and 2019, the number of people affected by hypertension increased considerably from 650 million to 1.3 billion. According to the WHO, one-third of the adult population is affected by AHT, with most cases occurring in low- and middle-income countries. According to the same report, only 54% of adults with hypertension are diagnosed, 42% receive treatment, and only 21% have their blood pressure under control.
These numbers highlight the urgent need for increased awareness and improved management of this so-called silent disease. Patients often remain asymptomatic for many months or even years, delaying diagnosis, which could thus lead to inadequate management. The WHO report also indicates that nearly four out of five people with hypertension do not receive adequate medical care. However, improving access to treatment could prevent 76 million deaths between 2023 and 2050.
Unknown origin
AHT is a cardiovascular condition characterized by an abnormal increase in blood pressure against the artery walls (140/90 mmHg or higher). It can be classified into two main categories: essential hypertension and secondary hypertension. Essential hypertension, also known as primary hypertension, is the most common form, accounting for nearly 95% of cases. It is termed idiopathic, meaning it develops without an identifiable specific cause.
On the other hand, secondary hypertension is caused by identifiable underlying factors, such as kidney, adrenal, vascular, or endocrine disorders, some medications (such as corticosteroids, non-steroidal anti-inflammatory drugs, nasal decongestants, oral contraceptives and certain anti-migraine drugs), or exceptionally rare genetic conditions (like familial hyperkalemic hypertension, also known as Gordon syndrome).
Polygenic pathology
While the direct causes remain largely unknown, several factors can increase the risk of developing hypertension. Among these, some are environmental and thus potentially modifiable, or at the very least, controllable, such as smoking, a high-salt diet, high cholesterol levels, diabetes, obesity and a sedentary lifestyle.
Another factor seems to be related to genetic birth predisposition, due to a person’s genetic code. Numerous genome-wide association studies (which identify common genetic variations associated with a disease across the entire genome, Editor’s Note), have shed light on the complex genetic structure of hypertension, which is distinctly polygenic. Essentially, AHT is influenced by multiple genes acting in combination.
A recent study, published on April 30th in Nature Genetics, aimed to identify new genomic regions linked to blood pressure. This extensive study, one of the largest of its kind on this condition, incorporated data from over a million participants. It provides a solid groundwork for researchers to deepen their understanding of blood pressure regulation mechanisms and, consequently, pinpoint new targets for the development of antihypertensive drugs. The finding of this study are based on the analysis of a database pooled from four genome-wide association studies involving a sample of 1,028,980 adults.
New genetic Ioci
According to the findings published by Keaton et al., 113 new regions of the human genome, also known as genetic loci, have been identified as potentially influencing an individual’s blood pressure. The publication suggests that “these new genetic insights may provide opportunities for further experimentation in model systems and identify potential targets for drug development or repurposing.”
Furthermore, researchers were able to calculate a polygenic risk score, combining the effects of all genomic variants, which predicts the risk of hypertension. Although the collected data primarily stems from individuals of European descent, the researchers observed that this score is also relevant to individuals of African descent.
The results also indicate that iron metabolism might influence blood pressure regulation and cardiovascular diseases linked to hypertension. This finding aligns with previous studies correlating excess iron with cardiovascular diseases. While these findings are promising, the authors stress the need for pursuing efforts to further expand the sample size, thereby strengthening correlations.
Such research initiatives could pave the way for more effective preventive and therapeutic measures to reduce the detrimental impact of AHT on overall health.
